Few Ultimate Doom WADs have stood the test of time as well as the 2011 E1 replacement "Double Impact" by RottKing and Ralphis, a collection of sprawling techbases with agile action. In addition to being released as a standalone PWAD, Double Impact became the fourth episode of the IWAD replacement Freedoom: Phase 1 in 2013, and in 2020 became an official add-on for the Unity port of Doom, introducing it to a wider audience than even the best Doom WADs usually receive.

One small flaw in this otherwise great WAD is its incomplete soundtrack. The original PWAD contained two original tracks and two remixes of Bobby Prince's music. In Freedoom, due to the limitations of the engine, Double Impact simply reuses music from the first three episodes, in the same pattern that Ultimate Doom's fourth episode did, meaning that the music selections fit only a little better than random chance. This project aims to fix that flaw by providing a new soundtrack for the WAD that can be used with both the PWAD and Freedoom: Phase 1, and which, in the spirit of Freedoom, is absolutely free to reuse and remix.

Three WADs are included in the ZIP file: dbmid_e1.wad replaces all non-original tracks in the Double Impact PWAD; dbmid_e4.wad replaces the tracks for maps in Freedoom's fourth episode; and dbmide4v.wad replaces the tracks that are reused by E4 maps in vanilla source ports for use Freedoom's fourth episode.